The church consists of a nave, chancel and apse, without a tower today. Sources agree that a tower once stood but was demolished in 1722 and replaced by a freestanding bell frame just west of the church, where two bells—cast in 1801 and 1860—still hang. The whitewashed limewashed facades and sandstone window and door surrounds give the building a plain but dignified medieval character.
According to an older Västgöta bishops' chronicle, Saint Sigfrid is said to have chosen the site and consecrated the churchyard, reportedly in the early eleventh century, though other accounts place this tradition more loosely around the time of his visits to the region. The church later became known as an 'offerkyrka', a church popularly believed to hold special spiritual power, where gifts or offerings were thought to improve the chance of prayers being answered.
Renovation work in 1952–1953 uncovered a stone-lined grave beneath the apse, dated to around 1100–1150. Because this predates the present stone church, it is thought an earlier wooden church may have stood on the same site, with the grave originally located within its walls.
Inside, the vaulted medieval crossed-rib ceiling is a notable survival; one source notes that in the 1600s it was decorated with lively curtain-like ornamentation in a mixed baroque-rococo style, later limewashed over and repainted plainly during the 1892 restoration, when two windows were also opened in the previously blank north wall.
Among the furnishings, the sandstone font dates from the mid-thirteenth century and belongs to the so-called Remmene group of fonts, recognisable by its rounded bowl and base divided by a thick rope-like moulding. The altarpiece of 1715, attributed to the sculptor Jonas Ullberg (sources differ slightly on whether this was Jonas Ullberg or his son), depicts the Crucifixion flanked by figures of Moses and John the Baptist. The pulpit, made in 1699 by Johan Ullberg the elder, originally stood in the royal estate church at Ettak before that building fell into ruin; Östra Gerum's congregation bought it in 1729 for 50 silver daler. The church also has a small organ from 1903, rebuilt in 1979, with three stops.